Digital projectors are used in media presentation environments such as business meetings, home theaters and the like. In general, the digital projector has taken the place of overhead projectors, slide projectors, and other devices used for showing visual presentations. Usually, digital projectors consist of a digital display technology such as Liquid Crystal Display (LCD), Digital Light Processing (DLP), or the like, for generating a digital image; and a light source for projecting the digital image. Herein, the terms display area or screen signifies the medium upon which the viewable projected image arrives.
For example, it is common in a meeting to connect a laptop or other computing system to a digital projector and then utilize the digital projector to project the content onto a display area that is significantly larger than the laptop's monitor. In so doing, everyone at the meeting can more easily observe the content (e.g., slideshow, video, real-time data, or the like).
In some applications, the digital projector is fixedly mounted, such as on the ceiling, and hardwired to an outlet or other computer system connector. However, in other applications, the digital projector may be portable.
Regardless of whether the digital projector is portable or fixedly mounted, there are a number of drawbacks with respect to the initial set-up of the digital projector. These drawbacks can be deleteriously time consuming and can cause significant user frustration.
For example, depending on the orientation between the digital projector and the selected display area, issues such as vertical and/or horizontal keystoning of the projected image may occur. In general, vertical keystoning refers to an image with varying width from top to bottom, while horizontal keystoning refers to an image with varying width from one side to the other.
Normally, vertical keystoning occurs when the digital projector is offset above or below the center of the display area. For example, if the digital projector is oriented below the center of the display area the lower portions of the projected image will travel a shorter distance than the upper portions. As such, the resultant projected image will appear “stretched” at the top or “squeezed” at the bottom.
In contrast, horizontal keystoning occurs when the digital projector is offset to one side of the display area. For example, if the digital projector is oriented to the right of the display area the right side of the projected image will travel a shorter distance than the left side. As such, the resultant projected image may appear “enlarged” toward the left, “shrunken” toward the right, or a combination thereof.
Either of the above stated keystoning issues will result in an undesirable projected image. Additionally, a combination of the above stated keystoning issues may result in a significantly skewed projected image requiring a number of corrective actions, none of which may be apparent. Moreover, if improper corrective actions are applied, one or both keystoning issues may be further exacerbated.